correct on 2 - you likely won't get a deterministic result (whatever you're updating it with but sounds like its date-based and not sure whether its a calendar or elapsed day etc etc) and the update will fail. You're best to manage the update based on a field value from the client side. You need some high availability solution and/or checks for your client-side issue that the update takes place. The ledger is not really the place to rely on applying your operational, schedule-based update.